This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. NMR Spectroscopy The samples were deuterium exchanged by dissolving in D2O (99.9 % D) and freeze-drying. The samples were then dissolved in D2O (99.96 % D) and placed in a 3-mm NMR tube. 1-D Proton NMR spectra were acquired on a Varian Inova-600 spectrometer at 25 [unreadable]C. Spectral width was 9615 Hz. For each sample 1024 scans were averaged. Chemical shifts were referenced to the HDO signal ([unreadable]=4.77 ppm at 25 [unreadable]C).